The Billion Ant Mega Colony and the Biggest War on Earth — Transcript

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1. 0:00In nearly every corner of the earth, ants wage war against each other.
2. 0:05Their weapons are what nature gave them. Some have strong armor, deathly stingers, or sharp mandibles.
3. 0:11And then there's this tiny and not very impressive ant,
4. 0:15but it rules the biggest empire any ant has ever built.
5. 0:19A colony spanning continents and fighting wars that leave millions of casualties.
6. 0:24Let's take a look at this unlikely warrioress,
7. 0:28"Linepithema humile" the Argentine ant.
8. 0:33♫ Kurzgesagt intro music ♫
9. 0:42This story begins in the floodplains around the Paraná River, in South America,
10. 0:47It's a crowded ant megalopolis where dozens of ant species fight for dominance,
11. 0:52including fire ants, army ants and the rather unimpressive Argentine ant.
12. 0:58It measures only 2 to 3 millimeters in length and with its small mandibles,
13. 1:02it's surprising that it survived among its buff competitors.
14. 1:07Their homes are equally unremarkable.
15. 1:09Their colonies range from fairly small to very large and could be found anywhere:
16. 1:14Under logs, in loose leaf litter or the former colonies of other ants.
17. 1:19Here, Argentine ants prepare their most effective weapon against their competitors: bodies.
18. 1:25Most ant species have only one queen to produce ants,
19. 1:29while Argentine ants went all-in on numbers.
20. 1:32For every 120 workers there's one queen,
21. 1:35laying up to 60 eggs a day.
22. 1:38So their colonies grow fast and have millions or billions of individuals.
23. 1:44Teams of queens and workers frequently branch out and found new colonies.
24. 1:50But this strategy has a downside: As colonies grow and produce a lot of offspring,
25. 1:55mutations occur and new colonies adapt to new environments.
26. 1:59Their DNA slowly changes from generation to generation and differences accumulate.
27. 2:04So after a while the ants that left the colony
28. 2:07will become more like distant cousins and start to compete with their mother colony.
29. 2:12In their native South American range, this is how Argentine ants behave.
30. 2:17Within their colonies they are very cooperative and well-organized,
31. 2:21but they fight vicious wars against other Argentine ant colonies and other ant species
32. 2:27With equally strong opponents on every side,
33. 2:30the Argentine ant became extremely aggressive, fighting for every inch of ground.
34. 2:35But it could never dominate its neighbours... until humans showed up.
35. 2:40We did what humans do and transported things around the world by ship.
36. 2:44On one of them, a few Argentine ant queens hitched a ride as stowaways
37. 2:48from South America to Madeira and New Orleans.
38. 2:52The Argentine ants suddenly found themselves in a strange world.
39. 2:57Instead of being surrounded by deadly enemies,
40. 2:59they found only victims ⁠— nobody could fight them effectively.
41. 3:04Because only a few Argentine ant queens were introduced to the outside world,
42. 3:09the resulting colonies had very low genetic diversity.
43. 3:13On top of that, the introduced Argentine ants
44. 3:15kill up to 90% of their queens every year.
45. 3:19Fewer queens, less genetic variation.
46. 3:22So, as these colonies spread across the landscape,
47. 3:25ants that left the colony were no longer considered distant cousins.
48. 3:29As a result, the new colonies form not opposing but cooperating parties called "supercolonies".
49. 3:37This is a very uncommon strategy in the ant kingdom,
50. 3:40only a few of the 16,000 ant species have evolved supercolonies.
51. 3:45A supercolony was established on the West coast of the USA
52. 3:49and became a base for the tiny ants' global conquest.
53. 3:53Today, the Argentine ant inhabits the Mediterranean zones of six continents and many islands.
54. 3:59This one supercolony was especially successful,
55. 4:02establishing sister locations in California, Europe, Japan, New Zealand and Australia,
56. 4:08forming one massive intercontinental megacolony of Argentine ants.
57. 4:13This makes them the largest society on Earth, more numerous than even the human one.
58. 4:19But their success has changed the ecosystems they invaded.
59. 4:23California is a perfect example of this.
60. 4:26In their greed for more territory,
61. 4:28the invading Argentine ants have overrun and replaced 90% of the native ant species,
62. 4:34including several species of Californian carpenter ants.
63. 4:38Although carpenter ant workers are giants,
64. 4:41their colonies have only between 3,000 and 6,000 individuals
65. 4:45and stand no chance against an expanding supercolony of billions of Argentine ants.
66. 4:51Argentine ant workers attack by wiping toxic chemicals on their victims
67. 4:55which irritates the enemy and marks them as a target for other Argentine ants.
68. 5:00When they attack, the Argentine ants wash over their victims,
69. 5:04clinging on to their opponents in groups and pulling apart their limbs.
70. 5:08It doesn't matter how many of them die ⁠— there are always more.
71. 5:12Once the colony is overrun and exterminated,
72. 5:15the Argentine ants feed on their victims brood and take over their home and territory.
73. 5:21The Argentine ants' numbers allow them to hunt down and devour such an excessive mass of different insects
74. 5:27that over time some species disappear from the ants' territory completely.
75. 5:31Argentine ants don't care about working with the local flora and fauna,
76. 5:36they consume them and move on.
77. 5:39And, if their next stop happens to be human property,
78. 5:41they will rudely make themselves at home there too.
79. 5:44They forage in dumpsters, bowls of pet food and sneak into kitchens to claim leftovers.
80. 5:50Not just our homes: our gardens and fields are also impacted by Argentine ants,
81. 5:55since they tend to hordes of aphids as their cattle.
82. 5:58The aphids feed from plants and produce a sweet honeydew, which they trade with the ants for protection.
83. 6:04Since the ants have no major enemy to fear in their new homes,
84. 6:07the aphids thrive and ultimately kill the plants they live on.
85. 6:11So, on top of being a major disruption for the ecosystems they invade,
86. 6:16they are also a huge pest for agriculture.
87. 6:20But the rule of the Argentine ant is being challenged.
88. 6:24Parts of the super colonies have broken off and become their own empires.
89. 6:28A merciless civil war has broken out.
90. 6:31For example, the Lake Hodges Supercolony has been fighting against the Very Large Colony
91. 6:36for years in San Diego County.
92. 6:38A massive war is going on over a dynamic front line stretching over kilometers,
93. 6:44an estimated 30 million ants die here each year.
94. 6:48On other fronts, an old acquaintance from the Parana River has risen from the shadows
95. 6:53Red imported fire ants,
96. 6:55which were accidentally introduced from their old home to the coast of Alabama,
97. 6:59Not only are the red fire ants fierce fighters and more than able to deal with the
98. 7:03Argentine ant, they are also able to form super colonies themselves.
99. 7:08Now the old wars from their distant home have been taken to a foreign battleground.
100. 7:14In the southeastern US the super colonies clashed fiercely.
101. 7:18The Argentine ants found themselves outgunned by the fire ants. The fire ants major workers are
102. 7:24more than twice the size of the Argentine ants and wield venom-injecting stingers,
103. 7:28even though the Argentine ants fought fiercely, the fire ants were too much for them.
104. 7:33After countless lost battles the red imported fire ant
105. 7:36exterminated the Argentine ants super colony from much of the southeastern US.
106. 7:42This is one territory lost but the Argentine ants will fight on.
107. 7:46This amazing network of cooperating super colonies is the biggest success in their history.
108. 7:52And they'll not give it up because of a small defeat.
109. 7:55They will stand their ground against any enemy that might arise.
110. 7:59No matter if it's on the Paraná River
111. 8:01or on one of the large battlefields across the world.
112. 8:06♫ Background music winds up ♫